CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:
#define CPU_MASK_ALL (cpumask_t) { { ... } }
Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:
#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)
Which formalizes this practice. One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).
[Description by Rusty Russell]
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
irq_choose_cpu() should compare the affinity mask against cpu_online_map
rather than CPU_MASK_ALL, since irq_select_affinity() sets the interrupt's
affinity mask to cpu_online_map "and" CPU_MASK_ALL (which ends up being
just cpu_online_map). The mask comparison in irq_choose_cpu() will always
fail since the two masks are not the same. So the CPU chosen is the first CPU
in the intersection of cpu_online_map and CPU_MASK_ALL, which is always CPU0.
That means all interrupts are reassigned to CPU0...
Distributing interrupts to CPUs in a linearly increasing round robin fashion
is not optimal for the UltraSPARC T1/T2. Also, the irq_rover in
irq_choose_cpu() causes an interrupt to be assigned to a different
processor each time the interrupt is allocated and released. This may lead
to an unbalanced distribution over time.
A static mapping of interrupts to processors is done to optimize and balance
interrupt distribution. For the T1/T2, interrupts are spread to different
cores first, and then to strands within a core.
The following is some benchmarks showing the effects of interrupt
distribution on a T2. The test was done with iperf using a pair of T5220
boxes, each with a 10GBe NIU (XAUI) connected back to back.
TCP | Stock Linear RR IRQ Optimized IRQ
Streams | 2.6.30-rc5 Distribution Distribution
| GBits/sec GBits/sec GBits/sec
--------+-----------------------------------------
1 0.839 0.862 0.868
8 1.16 4.96 5.88
16 1.15 6.40 8.04
100 1.09 7.28 8.68
Signed-off-by: Hong H. Pham <hong.pham@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This gets us real close to the generic implementation of
setup_per_cpu_areas() except:
1) We store the per-cpu offset into the trap_block[], whereas
the generic code has it's own static array.
2) We have to initialize the %g5 register to hold the boot cpu's
per-cpu area offset.
3) The OBP/MDESC cpu info scan is performed at the end.
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we defer the cpu_data() initializations to the end of per-cpu
setup, we can get rid of this local hack we had to setup the per-cpu
areas eary.
This is a necessary step in order to support HAVE_DYNAMIC_PER_CPU_AREA
since the per-cpu setup must run when page structs are available.
Signed-off-by: David S. Miller <davem@davemloft.net>
This really isn't necessary at all, a local variable suits the
job just fine.
This frees up 8 bytes in the trap_block[] that we can use later
to store the per-cpu base addresses.
Signed-off-by: David S. Miller <davem@davemloft.net>
Interrupts must be disabled when taking the IPI lock.
Caught by lockdep.
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
As explained by Benjamin Herrenschmidt:
> CPU 0 is running the context, task->mm == task->active_mm == your
> context. The CPU is in userspace happily churning things.
>
> CPU 1 used to run it, not anymore, it's now running fancyfsd which
> is a kernel thread, but current->active_mm still points to that
> same context.
>
> Because there's only one "real" user, mm_users is 1 (but mm_count is
> elevated, it's just that the presence on CPU 1 as active_mm has no
> effect on mm_count().
>
> At this point, fancyfsd decides to invalidate a mapping currently mapped
> by that context, for example because a networked file has changed
> remotely or something like that, using unmap_mapping_ranges().
>
> So CPU 1 goes into the zapping code, which eventually ends up calling
> flush_tlb_pending(). Your test will succeed, as current->active_mm is
> indeed the target mm for the flush, and mm_users is indeed 1. So you
> will -not- send an IPI to the other CPU, and CPU 0 will continue happily
> accessing the pages that should have been unmapped.
To fix this problem, check ->mm instead of ->active_mm, and this
means:
> So if you test current->mm, you effectively account for mm_users == 1,
> so the only way the mm can be active on another processor is as a lazy
> mm for a kernel thread. So your test should work properly as long
> as you don't have a HW that will do speculative TLB reloads into the
> TLB on that other CPU (and even if you do, you flush-on-switch-in should
> get rid of any crap here).
And therefore we should be OK.
Signed-off-by: David S. Miller <davem@davemloft.net>
Makes code futureproof against the impending change to mm->cpu_vm_mask.
It's also a chance to use the new cpumask_ ops which take a pointer
(the older ones are deprecated, but there's no hurry for arch code).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We're weaning the core code off handing cpumask's around on-stack.
This introduces arch_send_call_function_ipi_mask(), and by defining
it, the old arch_send_call_function_ipi is defined by the core code.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: Use new API
Change smp_call_function_mask() callers to smp_call_function_many().
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Andrew Morton wrote:
People keep on doing
printk("%llu", some_u64);
testing it only on x86_64 and this generates a warning storm on
powerpc, sparc64, etc. Because they use `long', not `long long'.
Quite a few 64-bit architectures are using `long' for their
s64/u64 types. We should convert them all to `long long'.
Update types.h so we use unsigned long long for u64 and
fix all warnings in sparc64 code.
Tested with an allnoconfig, defconfig and allmodconfig builds.
This patch introduces additional warnings in several drivers.
These will be dealt with in separate patches.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits)
x86: export vector_used_by_percpu_irq
x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and()
sched: nominate preferred wakeup cpu, fix
x86: fix lguest used_vectors breakage, -v2
x86: fix warning in arch/x86/kernel/io_apic.c
sched: fix warning in kernel/sched.c
sched: move test_sd_parent() to an SMP section of sched.h
sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
sched: activate active load balancing in new idle cpus
sched: bias task wakeups to preferred semi-idle packages
sched: nominate preferred wakeup cpu
sched: favour lower logical cpu number for sched_mc balance
sched: framework for sched_mc/smt_power_savings=N
sched: convert BALANCE_FOR_xx_POWER to inline functions
x86: use possible_cpus=NUM to extend the possible cpus allowed
x86: fix cpu_mask_to_apicid_and to include cpu_online_mask
x86: update io_apic.c to the new cpumask code
x86: Introduce topology_core_cpumask()/topology_thread_cpumask()
x86: xen: use smp_call_function_many()
x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c
...
Fixed up trivial conflict in kernel/time/tick-sched.c manually
Simple replacement, now the _nr is redundant.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
o Move all files from sparc64/kernel/ to sparc/kernel
- rename as appropriate
o Update sparc/Makefile to the changes
o Update sparc/kernel/Makefile to include the sparc64 files
NOTE: This commit changes link order on sparc64!
Link order had to change for either of sparc32 and sparc64.
And assuming sparc64 see more testing than sparc32 change link
order on sparc64 where issues will be caught faster.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stephen Rothwell